noun.
The act or process of improving something or the state of being improved.
noun.
An improvement.
noun.
The linguistic process by which a word over a period of time grows more elevated in meaning or more positive in connotation.
The Century Dictionary and Cyclopedia
noun.
The act or process of making or becoming better; improvement; amelioration.
noun.plural In Scots law, improvements made by a tenant upon the property which he rents, and for which he is in certain cases entitled to compensation from the landlord.
the GNU version of the Collaborative International Dictionary of English
noun.
The act or operation of meliorating, or the state of being meliorated; improvement.